Various types of analytical tests related to patient diagnosis and therapy can be performed by analysis of a liquid sample taken from a patient's bodily fluids, or abscesses. These assays are typically conducted with automated clinical analyzers onto which tubes or vials containing patient samples have been loaded. The analyzer extracts a liquid sample from the vial and combines the sample with various reagents in special reaction cuvettes or tubes (referred to generally as reaction vessels). Usually the sample-reagent solution is incubated or otherwise processed before being analyzed. Analytical measurements are often performed using a beam of interrogating radiation interacting with the sample-reagent combination, for example, turbidimetric, fluorometric, absorption readings, or the like. The measurements allow determination of end-point or rate values from which an amount of analyte related to the health of the patient may be determined using well-known calibration techniques.
Clinical chemistry analyzers typically include a plurality of stations or modules that interact with patient samples. Each module can be specialized to a type of test, calibration, or sample handling task. Commonly, an automation system is employed to shuttle samples from one module to another, allowing each module to perform tasks on the patient sample in an automated fashion. Traditionally, such automation systems have included slow speed friction tracks (<1 m/sec) that slowly move patient samples from one point to another point in the automation system. This can result in long latency and low throughput. For example, if an analyzer is 50 meters from the sample entry point, and the track is operating at a speed of 0.2 m/sec, it will take 250 seconds (over 4 minutes) from the sample entry until it is received by the analyzer. This transport time adds to the overall turnaround time (TAT) of samples analyzed by the system and is undesired.
It is desirable for patient samples to move through the automation system as quickly as possible to reduce overall system latency. An example of an automation system that can be used to reduce the transit time of patient samples in an automation system can be found in commonly owned U.S. patent application Ser. No. 14/376,107, incorporated herein by its entirety.
While it is desirable to minimize transit times on an automation track, traditionally speeds were limited intentionally to minimize acceleration and jerk forces applied to patient samples. Typically, patient samples are transported in patient sample tubes, such as test tubes. Because capping and uncapping a sample tube is a precise mechanical operation, capping and uncapping operations are typically handled by hand or by the use of a dedicated capper/decapper station that has been developed to precisely remove and align and apply caps to patient sample tubes. As result, sample tubes are typically de-capped, placed into the automation system, shuttled between various modules, portions of that sample are aspirated at each module, and the sample tube is returned for recapping by hand or at a dedicated capping station. Thus, patient samples are often moved via the automation system in an uncapped state.
Because of the biohazardous and sensitive nature of patient samples, it is desirable, and often a requirement, that the automation system does not cause spilling of the patient sample, which could contaminate the automation track or other samples. The traditional way this was accomplished has been by reducing the overall speed of the automation system, so as to minimize forces on the patient sample tube. This prevents splashing, spilling, and frothing, but reduces the overall speed of the automation system, increasing latency.